--- cli-script.c.orig	2010-05-17 22:28:12.000000000 +0300
+++ cli-script.c	2011-03-09 11:37:04.917093842 +0200
@@ -1416,8 +1350,9 @@
       CMD_POST_HOOK
     };
   struct command_line *cmds;
-  struct cmd_list_element *c, *newc, *hookc = 0, **list;
-  char *tem, *comfull;
+  struct cmd_list_element *c, *newc, *hookc = 0, **list;
+  char *tem, *tem2, *comfull;
+  char tembuf[MAX_TMPBUF];
   char tmpbuf[MAX_TMPBUF];
   int  hook_type      = CMD_NO_HOOK;
   int  hook_name_size = 0;
--- cli-script.c.orig	2010-05-17 22:28:12.000000000 +0300
+++ cli-script.c	2011-03-09 11:37:04.917093842 +0200
@@ -1430,8 +1365,11 @@
   comfull = comname;
   list = validate_comname (&comname);
 
+  strncpy(tembuf, comname, MAX_TMPBUF);
+  tembuf[MAX_TMPBUF-1] = 0;
+
   /* Look it up, and verify that we got an exact match.  */
-  tem = comname;
+  tem = tembuf;
   c = lookup_cmd (&tem, *list, "", -1, 1);
   if (c && strcmp (comname, c->name) != 0)
     c = 0;
--- cli-script.c.orig	2010-05-17 22:28:12.000000000 +0300
+++ cli-script.c	2011-03-09 11:37:04.917093842 +0200
@@ -1465,11 +1402,26 @@
    
   if (hook_type != CMD_NO_HOOK)
     {
+      /* Convert _ characters into spaces, to allow hooking prefix commands */
+      tem = tembuf + hook_name_size;
+      tem2 = strchr(tem, '_');
+      while (tem2)
+        {
+          *tem2 = ' ';
+          tem2 = strchr(tem2+1, '_');
+        }
+
       /* Look up cmd it hooks, and verify that we got an exact match.  */
-      tem = comname + hook_name_size;
       hookc = lookup_cmd (&tem, *list, "", -1, 0);
-      if (hookc && strcmp (comname + hook_name_size, hookc->name) != 0)
+      while (hookc && *tem)
+        {
+          /* tem might point to the argument of a prefix command */
+          if (hookc->prefixlist)
+              hookc = lookup_cmd (&tem, *hookc->prefixlist, "", -1, 0);
+          else
 	hookc = 0;
+        }
+
       if (!hookc)
 	{
 	  warning (_("Your new `%s' command does not hook any existing command."),